Dr. Wright, a long-term visiting scientist, is working primarily with NFCR staff learning flow cytometry techniques and applying them in the following areas. They are developing cell lines expressing green fluorescent protein and methods of selecting them with the goal of tagging specific cells in mixed cell spheroid models. In another project, extracellular matrix effects on radiation resistance in human diploid fibroblasts and low dose radiation effects on cell cycle are being studied. Cell cycle analysis is also being used to quantify the response of butyrate-resistant cells to DNA damaging agents and the affects on expression of cyclin-dependent kinase inhibitors.